1. Technical Field
The present methods and systems relate to communications between wireless modules and a network, and more particularly, to efficient methods and systems for supporting secure, efficient, and flexible communications using Internet Protocol networks, where a server can communicate with both a “machine-to-machine” modules and an application.
2. Description of Related Art
The combination of “machine-to-machine” (M2M) communications and using low-cost sensors, Internet connections, and processors is a promising and growing field. Among many potential benefits, M2M technologies allow the remote monitoring of people, assets, or a location where manual monitoring is not economic, or costs can be significantly reduced by using automated monitoring as opposed to manual techniques. Prominent examples today include vending machines, automobiles, alarm systems, and remote sensors. Fast growing markets for M2M applications today include tracking devices for shipping containers or pallets, health applications such as the remote monitoring of a person's glucose levels or heartbeat, monitoring of industrial equipment deployed in the field, and security systems. Many M2M applications leverage either wired Internet connections or wireless connections, and both types of connections continue to grow rapidly. M2M applications may also be referred to as “the Internet of things”.
M2M communications can provide remote control over actuators that may be connected to a M2M device, such as turning on or off a power switch, locking or unlocking a door, adjusting a speed of a motor, or similar remote control. A decision to change or adjust an actuator associated with an M2M device can utilize one or a series of sensor measurements. An M2M device may also be referred to as a “wireless module” or also simply a module. As one example, if a building or room is too cold, then temperature can be reported to a central server by an M2M device and the server can instruct the M2M device to turn on a switch that activates heat or adjusts a thermostat. As the costs for computer and networking hardware continue to decline, together with the growing ease of obtaining either wired or wireless Internet access for small form-factor devices, the number of economically favorable applications for M2M communications grows.
Many M2M applications can leverage wireless networking technologies. Wireless technologies such as wireless local area networks and wireless wide area networks have proliferated around the world over the past 15 years, and usage of these wireless networks is also expected to continue to grow. Wireless local area network (LAN) technologies include WiFi and wireless wide area network (WAN) technologies include 3rd Generation Partnership Project's (3GPP) 3rd Generation (3G) Universal Mobile Telecommunications System (UMTS) and 4th Generation (4G) Long-term Evolution (LTE), LTE Advanced, and the Institute of Electrical and Electronics Engineers' (IEEE) 802.16 standard, also known as WiMax. The use of wireless technologies with “machine-to-machine” communications creates new opportunities for the deployment of M2M modules in locations without fixed-wire Internet access, but also creates a significant new class of problems that need to be solved. First, many wireless wide-area networking standards were designed and optimized for mobile phones, which may be continuously connected to the network during the day (i.e. non-sleeping hours for most subscribers while they may charge phones at night), in order to receive inbound phone calls and messages. In this case, the radio may be in an idle state but utilizing discontinuous reception, but the radio is still active and drawing power in order to receive and process incoming signaling from the network such as a Public Land Mobile Network (PLMN). A need exists in the art to make wireless M2M communications efficient in order to conserve battery life and radio-frequency spectrum resources.
Since the packets transmitted and received by a wireless module will likely traverse the public Internet for many applications, a need exists in the art to (i) prevent eavesdropping at intermediate points along the path of packets transmitted and received, (ii) allow endpoints to verify the identity of the source of packets received. A need exists in the art for a wireless module and a monitoring server to leverage established public key infrastructure (PKI) techniques and algorithms. A need exists in the art for communication to be secured without requiring the established, but relatively processing, bandwidth, and energy intensive security protocols, such as IPSec, Transport Layer Security (TLS), and Secure Socket Layer (SSL). The establishment of theses links requires extra overhead in the form of packet handshakes and/or key exchanges at levels including the network and transport layer of the traditional Open Systems Interconnection (OSI) model. M2M applications frequently require small, periodic messages sent between a wireless module and a monitoring server, where the wireless module sleeps between the messages. M2M applications may leverage wired modules as well which also sleep between messages. During relatively long periods of sleep such as 30 minutes or more, the a wireless or wired network with intermediate firewalls will often tear down the network and/or transport layer connections, which means the wireless module would need to re-negotiate or reestablish the secure tunnels each time the wireless module wakes and seeks to send a relatively small message to a server. A need exists in the art for supporting established security protocols with an external application, without requiring them to be implemented on a module due to the relatively long periods of sleep and other complexities from inactivity in the module.
Next, a need exists in the art for the communication between a module and a monitoring server to be highly energy and bandwidth efficient in order to reduce energy consumption over the operating lifetime of a module. A limiting factor for a wireless module for M2M applications deployed or installed into the field is the lifetime of the battery of the wireless module. If the transmission techniques for the wireless module are not energy efficient, the system will require more frequent manual intervention for the replacement or recharging of batteries. If the battery becomes sufficiently low, then communication with the wireless module will be lost, or the frequency would have to be reduced for sensor measurements sent by the wireless module or actuator commands sent by a monitoring server. The energy saving techniques for transmitting and receiving data should leverage established Internet protocols, in order to utilize the public Internet, in addition to the need for secure communications noted above. For wired modules operating for years or decades, a significant cost will be the power consumed from land-line power.
Further, a need exists in the art for the secure, energy efficient communications that support Internet protocols to support intermediate firewalls that may exist along the path of packets sent and received by both a wireless module and a monitoring server. Without support for communication through an intermediate firewall, packets may be blocked by the firewall and the M2M application would not properly function in this case. A need exists in the art for techniques of secure and energy-efficient communications between modules and monitoring servers to support a wide variety of manufacturers of modules and M2M applications. Currently, there are dozens of manufacturers and form-factors of modules, and this diversity will continue to increase for the foreseeable future. By leveraging standards such as the Internet and PKI technologies, an efficient, secure, and highly scalable system of communicating could support the wide variety of modules.
In addition, the utilization of PKI technologies in modules can increase security, but a number of technical challenges must be addressed. These challenges increase if a deployed module required updated private/public key pairs after operation begins. The typical paradigm of “swapping out a SIM card” (which also depend on a pre-shared secret key Ki embedded in the card) with mobile phones may not be applicable or cost effective with modules, where swapping out the SIM card could be burdensome. A need exists in the art to allow for a deployed module to securely and automatically begin using new private and public keys (i.e. without human intervention such as swapping out a SIM card). Newer PKI technologies may offer a wide variety of algorithms for ciphering with public keys, and a need exists in the art for the utilization of new public and private keys to support the wide variety of algorithms, even after a module has been installed. In other words, a system should preferably both be highly secure and also flexible enough to adopt new security keys and standards. A need exists in the art for a scalable and secure method of associating a module identity with a module public key, when the module begins utilizing a new public key. A need exists in the art for a module to efficiently be able to utilize multiple public/private key pairs at the same time, such as with different service providers or different applications simultaneously.
Another desirable feature is for an M2M module to efficiently and securely communicate with applications. Applications can include a web-based interface for users to view status or input settings for a plurality of modules, and the modules may be associated with an M2M service provider. However, a set of PKI algorithms, keys, and communication protocols within used by the module for efficient communications module may not be directly compatible with an application. As one example, the application on a web server may prefer to use a transport layer security (TLS) protocol with transmission control protocol (TCP) datagrams, while for energy efficiency and to conserve battery life, an M2M module may prefer to use user datagram protocol (UDP). A need exists in the art for an intermediate server to securely translate secure communications to/from a module into secure communication from/to an application. As another example, it would be desirable for a module to support elliptic key cryptography (ECC), while the application may support RSA-based cryptography, and therefore a need exists in the art for a server to securely translate between the two cryptographic methods, thereby allowing the M2M module to communicate with the application.
And other needs exist in the art as well, as the list recited above is not meant to be exhaustive but rather illustrative.